1. Field of the Invention
The present invention relates generally to an apparatus and method for scarifying railroad beds, and more specifically, the present invention relates to an apparatus and method for forming a trench under a pair of parallel railroad tracks or rails and between an adjacent pair of ties contributing to the support of the rails.
2. Description of the Prior Art
Parallel tracks or rails for railroad trains are supported by wooden cross ties (generally referred to merely as "ties") located at spaced intervals along the tracks. These wooden ties decompose, work loose, or otherwise break or become insufficiently strong to support the rails and the trains that they carry. Accordingly, it is necessary to replace the wooden ties at periodic intervals.
Railroad bed ties are secured in place by various materials, all generally referred to as ballast. This ballast may be gravel, rocks, dirt, combinations thereof, or any other suitable materials. Thus, in replacing a tie, it is necessary to remove the ballast in order to insert the new tie under the railroad tracks. A trench formed in the ballast to receive the tie should have the desired shape to receive the tie and should place the ballast in a handy location for return after the new tie has been placed.
Various attempts have been made in the past to scarify or remove the ballast to provide the desired trench for the tie and appropriately handle the ballast. Such devices normally employ an action parallel to the ties. Such prior art devices involve a number of difficulties. For one thing, since they must work from outside the rails, they are normally cumbersome and difficult to operate. In addition, the resulting trenches are frequently not of the proper shape and location to easily receive the tie. Further, such devices normally deposit the ballast removed from under the tracks to one or both sides of the rails, so that it is difficult to return this ballast once the new tie is in place.
At least one prior art device has attempted to avoid the problems of these approaches by utilizing a plurality of rotating drums having an axis parallel to the ties. While such an approach more conveniently places the removed ballast on an adjacent tie, the radius of curvature results in a rounded bottom of the trench, which is undesirable for receiving the flat ties. In addition, if the drums are made sufficiently large to give a larger area at the bottom of the trench, there is considerable risk of disturbing adjacent ties.
Accordingly, prior art railroad bed scarifying apparatuses and methods have been less than completely satisfactory.